Motor controller



May 22, 1928.

F. F. DORSEY MOTOR CONTROLLER Original Filed April 50, 1924 IF'nQO ILO lmvmntm s Patented May 22, 1928.

6, UNITED STATESPATENT OFFICE.

FAB-HUM I. DORSEY, OF ROCHESTER, NEW YORK, ASSIGNOR TO NORTH EAST APPLI v ANCES, INC., OF ROCHESTER, NEW YORK,

A CORPORATION OF NEW-YORK.

\ MOTOR CONTROLLER.

Application filed April 30, 1924, Serial No. 710,091. Renewed November-15, 1927.

This invention relates to a device for starting and stopping an electric motor, and for controlling its speed of operation.

In a power-driven typewriter it is usual to employ an electric motor, and to provide a rheostat by which the speed of the motor may be controlled, so as to regulate the force with which the type-bars are actuated according to the kind of work for which the machine is being used. The object of the present invention is to provide simple and convenient means for controlling the motor in such power-operated typewriter, or in any other machine having similar requirements.

The invention consists in an arrangement in which a single manually-operable member serves both to start and Stop the motor and to change its speed of operation, and in which the current is broken by a snapaction, together with other advantageous features which will be set forth hereinafter.

In the accompanying drawings Fig. '1 is a side-elevation of a motor-controller em bodying the present invention, looking from the outside of the frame of the machine in which the controller is used,'and Fig. 2 is a side-elevation from the opposite point of view, with the rheostat and switch omitted.

Fig. 3 is a section on the line 3-3 in F ig.

o 2, looking downward. Fig. 4 is a plan View of the complete controller.

In the illustrated embodiment of the invention the flow of current to the motor is controlled by a rheostat5 provided with a series of contacts 6. A switch-arm 7 pivoted at 8 swings over these contacts, and in the off position it engages the uppermost contact, as shown in thedrawings, this being a dead contact.

The switch-arm is provided with parallel flanges 9 forming a channel which is engaged by a roller 10 of insulating material. The roller is mounted on a stud 11 projecting from a plate 12, and this plate is fixed on the inner endof a shaft 13, while a manually-operable knob 14 is fixed to the outer end of the shaft. The knob is provided with lugs 15 by which it may be conveniently turned. The shaft 13 is carried in a bearing-sleeve 16 seated in a boss 17 formed on the side-plate 18 of the frame of the machine, and the sleeve 16 is secured in place by a nut 19 on its outer end.

The movement of the knob and the rheostat is controlled by a stop-plate 20, which s mounted to turn loosely on the shouldered inner end 21 of the sleeve 16. The plate 12 carries two studs 22'which are adapted to enter two holes 23 in the stop-plate, and a compression-spring 24 tends to move the shaft 13 lengthwise in a direction to cause such engagement. lVhen the switch is in off position, however, the studs bear against the surface-of the stop-plate, as shown in the drawings.

The position of the stop-plate is determined by yielding means comprising a series of serrations 25 on the edge of the plate, and a detent-lug 26 which cooperates with them. The lug is on the lower end of an arm 27 of a bell-crank lever which swings on a pivot-screw 38 fixed on the frame 18 of the machine. The other arm 29 of the lever is engaged by one end of a spring 30 which is coiled around the boss 17, and this spring acts to hold the lug 26 in frictional engagement with the serrations 25. v

The spring 30 serves also to move the switch to off position when released from the stop-plate. For this purpose its other end 31 is offset and hooked around an arm 32 projecting from the plate 12. The lug 26, in addition. to the function already described, acts as a stop-lug, cooperating with a lug 33 on the plate 12, as'shown in Fig. 2, to arrest rotation of this plate when the switch has reached off position. It acts, finally, as a positive stop for the stop-plate 20, by cooperation with 2. lug 34 on the latter.

To indicate the speed at which the motor is running, the knob 14 is marked with figures 35, which coincide with a marker 36 on the frame 18.- v

The operation of the motor-controller is as follows: to start the motor, the user turns the knob 14 in the direction indicated by arrows in the drawings, thus causing the switch-arm to traverse the contacts of the rheostat and close the motor-circuit. This movement continues until the studs 22 on the plate 12 register with the holes 23 in the stop-plate 20, whereupon the spring 24 moves the shaft 13 endwise and causes the studs to enter the holes and thus arrest movement of the knob and of the switch-arm. The speed of the motor now depends upon the position of the switch-arm, and this is determined by the position in which the stopplate happens to be held by the detent-lug 26, in cooperation with the serrations 25.

IVhen it is desired to stop the motor, it is necessary only to push inwardly against the knob 14. This causes the studs 22 to be disengaged from the stop-plate, whereupon the spring 30 at once snaps the switch back to off position.

So long as the stop-plate remains undisturbed, the motor, when started by turning It will be seen that all of the functions of the controller are performed through different motions of a single manually-operable.

member, the knob 14. The motor is started. and its speed changed, by turning this knob, while it is stopped by pushing upon the knob. w

In a typewriter it is desirable to lock the keys against operation when the motor is idle, and Fig. 2 shows an arrangementby which this maybe accomplished. The keylevers 38 of the machineare extended forwardly above the motor-controller, and they cooperate with a flat locking-bar 37 which is pivoted on an axis 39 at its lower edge. An arm 40 projects laterally from the locking bar, and when the switch is .in ofi position the arm 32 on the controller engages the arm 40 and holds the locking-bar in operative position, as shown in full lines, so that the keys cannot be depressed. As soon, however,as the controller is moved to start the motor, the arm 40 is released and falls, rocking the bar to the position shown in dotted lines and freeing the key-levers.

The invention is not limited to the embodiment thereof hereinhefore described and illustrated in the drawings, but it may be embodied in various other forms within the scope of the following claims.

The invention claimed is:

1. In a motor-controller, the combination, with a rheostat, of a manually-operable control-member rotatable to move the rheostat to different positions; a stop-member for arresting movement of said control-member;

yielding means for holding the stop-member in any one of several positions; means for interlocking the. control-member with the stop-member when free movement of the former has been arrested by the latter; the control-member being bodily movable in the direction ofits axis to disengage the inter locking means; and resilient means tending to move the control-member axially in the opposite direction and to rotate it in a direction to move the rheostat to off position.

2. In a motor-controller, the combination of a switch-member; a look; a manuallyoperable member, with which the switchmember and the lock areoperably connected, rotatable in one direction to close the switch and release the lock and in the opposite direction to open the switch and throw the look into operation; and meansjor retaining the manually-operable member against such opposite rotation, said member being disengageable from theretaining-means by axial movement.

3. In a, motor-controller, the combination,

with a series of stationary contacts, and a contact-member movable across'the contacts, of a manually-operable control-member connected with said contact member and movable in one plane to actuate. the latter; a

stop-member for arresting movement of said control-member; yielding means for holding the stop-member in adjusted position; and resilient means tending to move the controlmember in one direction in its said plane'of movement; thecontrol-member being yieldable in a direction at an angle to said plane,

. to permit it to be disengaged from the stopmember.

' FARNUM r. DORSEY. 

